Can Cinnamon Fight Cancer?

It’s too bad that the wordproliferationhas such bad connotations. We generally hear of it in reference to things we don’t like, such as weeds, graffiti, strip malls, and nuclear weapons. Proliferation would sound pretty good in reference to things such as truffles, rainbows, tax cuts, and responsible behavior in teenagers, wouldn’t it? Kids are a reminder, of course, that we humans tend to proliferate (the word comes from the Latin for “to bear offspring”). The Bible says, “Be fruitful, and multiply.” And have we ever!

Whether or not human proliferation is a good thing is a matter of opinion, of course. Deep down inside all of us, however, proliferation definitely assumes the mantle of villain, because there, at the cellular level, it is usually associated with something we all dread: cancer. In cancer, cells proliferate by multiplying beyond the limits of growth and development that normally keep our body’s organs and systems in balance. And how do our cells multiply? By dividing, of course. (They didn’t explainthattrick in grade school, did they?)

When Bad Things Happen to Good Cells

When cells divide, each of the two new cells contains within it all the genetic information that was contained in the parent cell. This information is encoded in life’s master molecule, DNA, which is found, in the form of chromosomes, inside the nucleus of every cell (human cells contain 46 chromosomes). After cell division, each of the two new cells is itself capable of dividing, thus allowing the number of cells to increase exponentially (1 to 2 to 4 to 8 to 16, etc.). In an adult human, there are about 10 million cell divisions per second, to compensate for the 10 million cells that die every second. Some types of cells divide frequently (on a scale of hours or days), while others remain stable for long periods. Liver cells, e.g., divide only about once per year, and mature nerve cells never divide.

Only about half as many cinnamon-treated cells as control cells were counted, i.e., their proliferation had been effectively halted—not bad for a common kitchen spice!

Under normal conditions, the process of cellular reproduction, which is vital for the survival and success of every organism, is controlled by physiological mechanisms that maintain a proper balance between the birth of new cells and the death of old ones. If these control mechanisms fail, however, and the process runs amok, so to speak, there can be a rapid multiplication (through division) of the cells—cellular proliferation,which leads to a tumor. Sometimes the tumor is benign (whew!), but sometimes it’s malignant, and we all know what that means: cancer. (For a primer on this dreadful disease, see the sidebar “Cancer and the Cell Cycle.”)

Cancer and the Cell Cycle

To most people, the word tumor means cancer—and few things strike more fear into our hearts, despite all the medical advances that have made cancer a much more tractable disease—especially with early detection—than it used to be. Of course, many tumors arenotmalignant, but benign. Although they can be harmful in various ways, their cells will eventually stop dividing, bringing their growth to a halt. By contrast, malignant cells never stop dividing (biologists call them immortal) until they are killed or they kill their host organism, whichever comes first.

Furthermore, as a malignant tumor grows, some cells will eventually break away and travel to other parts of the body via the blood or lymph. This ismetastasis,one of the hallmarks of cancer, and it is what usually kills the patient. Other hallmarks are the tumors’ tendency to invade surrounding tissues and to recur after their attempted removal. (For further insight on this subject, see“Mastic Kills Colon Cancer Cells”in the September 2005 issue.)

Cancer is a complex disease that takes many different forms and poses great challenges for diagnosis and treatment. Of the many types of cancer, perhaps the oddest ischimney sweep’s cancer,a skin carcinoma of the scrotum, occurring as an occupational disease in that now nearly extinct class of workers. It was the first reported form (in the eighteenth century) of an occupational cancer.

Regardless of their form, all cancers begin with mutations in our DNA molecules, caused by ionizing radiation or various chemical agents, primarily pro-oxidants such as free radicals. With a sufficient number of mutations of certain kinds, the process of cell division becomes corrupted, in a sense. The normal cellular control mechanisms are overridden, and proliferation ensues. This is caused by a dysfunction in thecell cycle,the sequence of events occurring between one cell division and the next.

The cell cycle consists of four stages, called G1, S, G2, and M. The two G stages (G stands forgrowth) are metabolically active preparatory periods for the two stages where the most dramatic action occurs: S (for DNAsynthesisby replication) and M (formitosis). Mitosis is the process by which the cell’s nucleus divides; this is followed quickly bycytokinesis(included in the M stage), the division of the cell itself into two new cells, each with its own nucleus. The cycle then begins anew.

These four stages entail two crucial processes that alternate in succession: (1) the S-stagedoublingof the genome (the complete set of the organism’s chromosomes, containing all of its nuclear DNA), and (2) the M-stagehalvingof the doubled genome, thereby creating two clones of the original genome, each with the same number of chromosomes as in the parent cell.

The entire process is extremely complex and is exquisitely regulated by a variety of proteins that are synthesized (and destroyed) at different stages of the cycle to accomplish various tasks. Among these are the molecular “proofreading” of events to ensure that they unfold according to plan, and their interruption if they do not. Think of these proteins as tiny quality control inspectors, all acting strictly according to the laws of chemistry.

One such protein, called p53, is particularly important because it can sense damage to the DNA molecules and can interrupt the cell cycle during G1(before DNA replication can occur) until the damage can be repaired by other proteins. If p53 “decides” that the damage is too extensive to repair, it has another trick up its sleeve: it can trigger a process calledapoptosis,or cellular suicide. The hopelessly damaged cell destroys itself so that it cannot harm the organism (e.g., you) by dividing and thus possibly initiating a tumor. Thus, p53 is a tumor suppressor.

The trouble is that no tumor-suppression system is perfect, so tumors can still develop. Furthermore, if thep53gene (which codes for the p53 protein) is itself damaged by mutation, the protein can be incapacitated or eliminated, leaving the door open for tumors, some of which will likely be malignant. It turns out, in fact, that more than half of all human cancers harborp53gene mutations and have no functioning p53 proteins.

One might think, therefore, that increasing the amount of p53 in our systems (if that were possible) would be highly beneficial, by helping to prevent cancer. But nothing is that simple. Too much p53 can interfere with the normal and necessary process of cellular reproduction, thereby accelerating the aging process. Laboratory animals with enhanced expression of thep53gene have fewer cancers, but they tend to die young from “old age.”

The Science (Not Magic) ofCinnamon . . .

Wouldn’t it be great if there were some kind of magic powder that one could sprinkle on a malignant tumor and make it shrink? In a sense, that is what happened in a study published recently by researchers at the United States Department of Agriculture in Maryland—although there was, of course, no magic involved, just science (which sometimes has the appearance of magic when it produces startling results).1

The powder used wascinnamon,in the form of a water-soluble extract of cinnamon bark. The extract contains certain compounds that are strongly insulin-mimetic, i.e., they mimic the action of insulin in the body, thereby helping to control type 2 diabetes by regulating blood sugar levels.* These water-soluble compounds are calledprocyanidins (type A).Another water-soluble component of cinnamon, MHCP (methylhydroxychalcone polymer), was until recently thought to be primarily responsible for cinnamon’s insulin-mimetic properties.

*It’s fortunate that the most beneficial compounds in cinnamon are water-soluble, because certain oil-soluble compounds in cinnamon, notably the anticoagulant coumarin, are potentially harmful if taken in large quantities. This is why supplemental cinnamon should be taken only as a water-soluble extract.

. . . Resides in Its Polyphenols

The procyanidins (type A) and MHCP arepolymeric polyphenols,i.e., they are polymers consisting of molecular units each of whose structure incorporates more than one (poly) of a certain type of atomic configuration (phenol). Many plant polyphenols—of which there are thousands—are noted for their beneficial biological actions, particularly as antioxidants, and recent research has suggested that certain such compounds have protective effects against various forms ofcancer.2,3This has been ascribed, for the most part, to the polyphenols’ antioxidant properties.

That factor alone, however, cannot entirely explain the polyphenols’ biological actions, in the view of many scientists, who believe that other possible mechanisms include the inhibition or stimulation of enzymes that play key roles in cellular differentiation, proliferation, and death.1

Can Cinnamon Fight Leukemia and Lymphoma?

In the cinnamon study, the USDA researchers used cancer-cell cultures that were undergoing exponential growth. For such studies, scientists can use cell lines that originated naturally in actual cancers and that have been maintained under controlled conditions for laboratory use, or they can take normal cells and make them cancerous by using certain types of radiation, chemicals, or viruses as cancer-causing agents.

In this case, the researchers used three types of human cancer cells: two representing leukemia and one representing lymphoma. The former disease entails the malignant proliferation of leukocytes, a type of cell found mainly in the blood; the latter entails the malignant proliferation of lymphocytes, the predominant type of cell in the lymph. The idea was to see whether a cinnamon extract could inhibit the proliferation of these cancer cells, and if so, how.

Cinnamon Halted Cell Proliferation by Interrupting the Cell Cycle

The results were striking: over a 24-hour period (the time required for one doubling of the cell population), the cinnamon extract dramatically reduced the rate of proliferation in all three types of cancer cells. It did this in a dose-dependent manner, i.e., the higher the concentration of cinnamon extract, the greater the reduction in proliferation rate. At the highest cinnamon concentration used, the cell counts were reduced by about 50% compared with the untreated control cells.

The fact that cinnamon seems to be beneficial for both diabetes and cancer is one bit of evidence suggesting that there may indeed be a connection between these diseases.

Thus, although the control cells proliferated to about twice their original number during the 24-hour period, only about half as many cinnamon-treated cells as control cells were counted, meaning that their proliferation had been effectively halted—not bad for a common kitchen spice!

The researchers were also able to ascertain that the cinnamon extract induced a blockage of the cell cycle at theG2/Mphase (see the aforementionedsidebarfor an explanation of the cell cycle). This means that mitosis (cell division) was thwarted, even though the synthesis phase (S) of the cell cycle was not. It appears that cinnamon may accomplish this trick by inhibiting the actions of certain phosphatases, which are enzymes that play a key role in facilitating mitosis.

Is There a Link Between Diabetes and Cancer?

It’s probably not coincidental that cinnamon’s regulation of phosphatase activity in our cells also underlies its ability to combat insulin resistance, a characteristic feature of type 2 diabetes. As our cells become increasingly resistant to insulin’s efforts to facilitate glucose transport from the bloodstream into the cells, the pancreas tries to compensate by producing more and more insulin. This can lead to the dangerous condition ofhyperinsulinemia,or excessive insulin levels in the blood. Some researchers have begun to focus their interest on the possible role of this condition in the development of cancer.4The fact that cinnamon seems to be beneficial for both diabetes and cancer is one bit of evidence suggesting that there may indeed be a connection between these diseases.

Three Cheers for Research!

According to world-renowned cancer authority Bruce Ames, of the University of California, Berkeley, the three main causes of cancer are: (1) smoking; (2) dietary imbalances (excess fat and calories, and inadequate fruits, vegetables, fiber, and calcium); and (3) chronic infections leading to chronic inflammation (e.g., hepatitis B and C viruses,Helicobacter pyloriinfection, and schistosomiasis).5All three of these factors can produce or exacerbate a pro-oxidant environment in our cells, and the reactive oxygen species (including free radicals) that are the defining feature of this condition are strongly implicated in the development of cancer.

Scientific evidence continues to mount in support of the health benefits of plant polyphenols found in a variety of foods, herbs, and spices (such as cinnamon). The research points to their antioxidant actions—and, increasingly, to other biochemical actions as well—to explain how they help us ward off disease and stay healthy. Three cheers for the proliferation of research of this kind!

For those who are concerned about maintaining healthy blood sugar levels and a healthy lipid profile, as well as other aspects of good health,cinnamonis a good idea. This herbal nutriant containsprocyanidins (type A),a class of bioflavonoids that mimic the functions of insulin in important ways.

The recommended daily serving of of aqueous cinnamon extract is the equivalent of about 1 heaping teaspoon (3.5 g) of whole-cinnamon powder—but without the fat-soluble constituents of cinnamon, some of which are undesirable in large amounts.

Caution:If you have diabetes, do not take any supplement that may affect your blood sugar levels without first consulting your physician. Diabetes is a serious disease requiring careful professional management.

Hyla Cass, M.D., is a nationally recognized expert in integrative medicine, Assistant Clinical Professor of Psychiatry at UCLA School of Medicine, and author of several popular books, includingNatural Highs: Supplements, Nutrition, and Mind/Body Techniques,and8 Weeks to Vibrant Health: A Woman’s Take-Charge Program to Restore Well-Being.